CartTree is not clonable

[rahul13ramesh]

CrossValidation with CartTree() results in a systemError. In particular, when one calls the evaluate function of a CrossValidation object, the error occurs.

Here is the complete script(with log file) that highlights the issue.
https://gist.github.com/Red-devilz/4b2c6cdc361bf4dcd5e5dc50b8ff3eef

The error is as follows :

SystemError: [ERROR] In file /build/shogun-V6YrEn/shogun-6.1.3/src/shogun/base/SGObject.cpp line 744: 
Could not create empty instance of "BinaryTreeMachineNode". The reason for this usually is that get_name() of the 
class returns something wrong, or that a class has a wrongly set generic type.

I believe the error occurs at this line but I could be wrong. An identical error affects StratifiedCrossValidation() also.

[karlnapf]

You are probably right. This means our random forests are not clonable. It has nothing to do with crossvalidation actually.

[karlnapf]

Actually I don't even understand why that clone is there in xvalidation. We removed the multicore version a while ago due to problems, so no clone is needed. puzzled. @vigsterkr any comments?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[vigsterkr]

this done